How can I roll my note 4 back to 5.1?

[OptiPrime]

Ever since I updated my phone to 5.1.1. I've had nothing but problems

-Screen turning off and locking while im typing
-lag
-wifi turning on and off on its own

How can i roll the phone back just one version? (my phone was running so smoothly)

I still like lollipop (so was the version before this one 5.0 or 5.1.0?) but 5.1.1. is making my phone a pain to use. the only app/launcher i think could even possibly be effecting it, is Omni-Swipe.

 

[Rukbat]

You can't "roll back" a ROM update, you have to flash the earlier ROM. See [Samsung] How to flash Stock ROM via ODIN. (It's really quite boring to flash a Samsung ROM.)